Dear friend,
If God is of little consequence, then one might ask why pray at all. But even if we aren’t interested in Him, still any and every good thing is the result of His generosity. Since He has given us everything, don’t you think we owe Him the acknowledgement of that fact?
St. Thomas Aquinas puts the worship of God under the virtue of justice. We owe Him the acknowledgement of the truth of who He is—which is what worship (latria) is. It’s the highest form of prayer we have. Then we also owe Him our gratitude. He told us to ask Him for what we need—not because He needs to know, but because we need to be grounded in reality, acknowledging our complete dependence on Him.
By asking for what we need, we don’t change His mind. But we do change ourselves—from assuming that we are independent and self-sufficient. If God wanted to end our existence, He wouldn’t have to do something; He’d have to stop doing something. He keeps us in existence at every moment.
Asking that His will be done, does not at all mean that His will is always done. He has given us free will so that we can counter His will and often do. When we ask that His will be done, we are praying that we, His creatures, will act in accord with what He wants of us.
In short: God has no need of changing, but WE do.
Fr. Vincent Serpa, O.P.